PMID 40474881

Research
All papers

The effects of L-citrulline supplementation on cerebrovascular function during sprint interval training in taekwondo athletes

Li A, Li H, Chen J

Question

Does short-term L-citrulline supplementation improve cerebrovascular recovery after sprint interval cycling in trained male taekwondo athletes?

Summary

In a double-blind randomized crossover study, 20 male taekwondo athletes took L-citrulline or placebo for 5 days before a sprint interval cycling session. L-citrulline improved the breath-holding index recovery measure after exercise but did not significantly change sprint power or pulse index.

Methodology

  • Male taekwondo athletes with provincial-or-higher competition experience
  • 20 participants.
  • Cycle ergometer.
  • Work intervals: 30 seconds maximal sprint.
  • Recovery: 3 minutes active recovery without resistance.
  • Intensity: Maximal pedaling against 0.075 kp/kg body weight.
  • 5-minute warm-up plus four sprints and recoveries.
  • Single test session per supplementation phase.
  • 5-day supplementation phase before test.
  • Double-blind randomized crossover supplementation trial
  • Breath-holding index, Pulse index, and Average power were tracked.

Outcomes

BHI recovery

L-citrulline improved delta BHI versus placebo after SIT.

Delta BHI 0.07 +/- 0.22 with L-citrulline vs -0.18 +/- 0.46 placebo; F=5.09, p=0.037, partial eta squared=0.22.

Improved

Average power

Average sprint power was not significantly different between conditions.

F=1.27, p=0.275, partial eta squared=0.07.

No clear change

Pulse index

Pulse index change did not significantly differ between conditions.

F=0.19, p=0.669, partial eta squared=0.01.

No clear change

Insights

  • This paper supports a narrow recovery-marker claim, not a performance claim.
  • The sprint protocol is reproducible but equipment-based and athlete-specific.
  • Consumer supplement messaging should note the small male-athlete crossover design.

Limitations

  • Small sample size.
  • Male taekwondo athletes only.
  • Short-term supplement and acute exercise design.
  • Surrogate cerebrovascular outcomes.
  • Diet, sleep, and stress were not fully controlled.

Safety

  • No adverse-event results were reported in the the paper.
  • Participants were medically screened and supplement allergies were exclusionary.